National Repository of Grey Literature 19 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Utilisation of the double bond in the synthesis of new types of molecular photoswitches applicable in biological systems
Bartošová, Aneta ; Ivanová, Lucia (referee) ; Cigánek, Martin (advisor)
This bachelor thesis deals with the synthesis and characterization of new advanced organic molecules with the utilization of the structure motive of the double bond for purposes of application as molecular photoswitches. The theoretical part of the thesis introduces the types of molecules, their characterization and the comparison of fundamental isomers. In the next, section, the mechanisms of isomerization are presented, synthesis via cross-coupling reaction, comparison of advantages and disadvantages of methods and possible application of these molecules in medicine, biological systems and in material chemistry. In the experimental part of the thesis, the multistep synthesis of two final derivatives with an imine bond is described, which can possibly secure the application of these original materials like molecular photoswitches.
Synthesis and characterization of derivatives of militarily important substances
Sláma, Michal ; Cigánek, Martin (referee) ; Mravcová, Ludmila (advisor)
The Organization for the prohibition of chemical weapons verifies the adherence to the Chemical weapons convention. To fulfil this objective, it is necessary to have reliable methods for the identification of chemical warfare agents. Gas chromatography is the most important method in analysis of chemical warfare agents. Central database of prohibited substance is yet not complete and is steadily updated over the years. The experimental part of the diploma thesis describes the preparation of alkyl methylphosphonates. Prepared substances were analysed by means of gas chromatography. Mass spectra and retention indices were obtained.
Preparation and study of a series of diketopyrrolopyrrole (DPP)-based polymers as photoactive substances
Solanský, Lukáš ; Richtár, Jan (referee) ; Cigánek, Martin (advisor)
The present diploma thesis deals with polymers based on organic pigments, their preparation, characterization and use as photoactive substances with a focus on artificial photosynthesis. The experimental part is devoted to the preparation of diketopyrrolopyrrole (DPP) based polymers. 7 DPP derivatives with 5 different side chains were prepared. The preparation of DPP polymers by Stille cross-coupling reaction and direct arylation were compared. Due to the higher efficiency and lower complexity of direct arylation, this polymerization method was used to prepare a series of 20 polymers consisting of a combination of 5 DPP derivatives and 4 comonomers. In the synthesis of several of the resulting polymers, the formation of an insoluble moiety was observed which could not be characterized by available methods, and even the subsequent application of such materials is not possible due to this. On the basis of the data obtained, it became apparent that in particular the bulky adamantane group and the comonomer tetrafluorobenzene were not suitable for the preparation of polymers, as they resulted in very limited soluble materials which, moreover, had a low degree of polymerization. In contrast, polymers containing butyl-TEG, octadecane, the comonomer thiophene and partially benzothiadiazole had degrees of polymerization in the range of 10-33 and exhibited excellent spectral and optoelectric properties. Tests of photocatalytic hydrogen evolution using DPP polymers are under development, but hydrogen was not demonstrably detected in initial measurements on selected polymer materials (P14 and P20).
Preparation of diketopyrrolopyrrole-based (DPP) polymers for organic electronics
Solanský, Lukáš ; Veselý, Dominik (referee) ; Cigánek, Martin (advisor)
The modern world is burdened by dependence on electricity and problems with its production. A very advantageous way to gain electricity is through photovoltaics. However, the production of silicon solar cells is demanding and expensive with a high impact on the environment. For this reason, there is an effort to switch to solar cells based on organic semiconductors. These include, for example, polymers based on diketopyrrolopyrrole (DPP). The theoretical part of this thesis deals with organic electronics, conductive polymers and DPP-based polymers, their properties and applications. It further describes the most common synthetic approaches to DPP-based polymers. The experimental part of this final work describes the preparation of intermediates necessary for the synthesis of the resulting DPP-based polymers using Stille reaction. The thiophene derivative of DPP was N,N'­alkylated and subsequently brominated. Furthermore, organotin intermediates were prepared, which together with the dibrominated DPP derivative participate in the polymerization.
Study of effect of side chains of organic semiconductors for bioelectronic applications
Ivanová, Lucia ; Cigánek, Martin (referee) ; Krajčovič, Jozef (advisor)
Organic bioelectronics is a relatively young but perspective science discipline that introduces the applicability of organic electronic materials in bioelectronic devices. The promising outlook for using these applications ranges from improving the quality of the disabled people's life to the development of artificial intelligence. The theoretical part describes the essential properties of semiconducting polymers for the utilization in bioelectronics and, moreover, it presents a way of improving these properties by the proper implementation of the side chains. It deals with the possibility of optimizing the biomimetic properties of conjugated polymers by using bio-inspired molecules as peripheral chains, specifically nucleic bases. The nucleobase groups introduced onto the polymer chain thus provide the synthetic molecules with the ability of self-assembly and recognition of each other. The second part of the thesis focuses on the modification of the adenine molecule, with the preparation of the key intermediate for Stille coupling. Subsequent cross-coupling reaction results in the extension of the adenine’s -conjugated system with the thiophene molecule.
Preparation and study of the reactivity of a new series of N, N'-substituted diketopyrrolopyrrole (DPP) for organic photonics
Cigánek, Martin ; Vyňuchal, Jan (referee) ; Krajčovič, Jozef (advisor)
Currently, the major trend is the development of materials that could be used for transformation of solar energy into electrical energy. Organic photovoltaics studies this area of interest and especially in recent years increasingly tries to put functional materials of organic origin into practice. These materials belong to a group of "high performance pigments" due to their exceptional and relatively stable properties. One of the most important molecules are the diketopyrrolopyrroles (DPP) derivatives. The theoretical part of this bachelor work describes the organic electronics and photonics, DPP derivatives, various synthetic routes of DPP, properties of particular DPP derivatives and the dependence of their properties on the used substituents. There are described separation and analytical methods most commonly used in organic synthesis too. The experimental part describes the preparation of the backbone DPP containing thiophene units. The following are the modifications of DPP backbones with N,N‘-alkylation and N,N‘-arylation.
Modification of Organic High Performance Pigments for Applications in Organic Electronics
Cigánek, Martin ; Imramovský, Aleš (referee) ; Vyňuchal, Jan (referee) ; Krajčovič, Jozef (advisor)
Dizertační práce pojednává o studiu, syntéze a chemické derivatizaci molekul spadajících do skupiny organických vysoce výkonných pigmentů a jejich potenciálním uplatnění v oblastech organické elektroniky. Teoretická část práce je zaměřena na nejnovější trendy v dané oblasti, a to jak z aplikačního potenciálu konkrétních derivátů, tak z pohledu syntetických možností a jejich strukturálních derivatizací. V experimentální části je pak podrobně popsána příprava pestré škály intermediátů a výsledných produktů, zahrnujících deriváty diketopyrrolopyrrolů (DPP), benzodifuranonu (BDF), epindolidionu (EP), naphthyridinedionu (NTD) a polymeru na bázi thiofenu (PT). Celkově bylo nasyntetizováno 103 molekul, přičemž 49 tvořily výsledné produkty, z nichž 27 bylo zcela nových, dosud nepublikovaných. Hlavním motivem derivatizace molekul pigmentů je zde inkorporace derivátů adamantanu do finálních struktur. V další části práce jsou blíže diskutovány jednotlivé chemické modifikace vedoucí k výsledným produktům. Na sérii N,N'-; N,O'- a O,O'-substituovaných derivátů DPP je popsána komplexní studie vlivu charakteru alkylových řetězců a také pozice jejich navázání v molekule DPP, a to nejen na selektivitu reakce, ale rovněž na optické i termické vlastnosti syntetizovaných produktů.
The synthesis and study of new derivatives of diketopyrrolopyrroles for organic electronics
Cigánek, Martin ; Maier, Lukáš (referee) ; Krajčovič, Jozef (advisor)
This diploma thesis describes organic pigments of diketopyrrolopyrroles (DDPs) possessing properties applicable in attractive and perspective areas of organic electronics and photonics. The modification of the DPP skeleton was performed by nucleophilic substitution by various alkyl chains and 5 series of DPP derivatives were prepared. The regioselectivity of N-alkylation and also the photophysical properties of the prepared derivatives were studied. A key product of this work is the N,N'-ethyladamantyl derivative of DPP, which exhibited ambipolar characteristic with excellent electron mobility of 0.2 cm2 V–1 s–1. Further, the -conjugation of the above-mentioned DPP derivative was extended by 1 and 2 thiophene units at positions 3,6 and the effect of this modification on optical properties of the resulting derivatives was investigated. A new modified N,N'-unsubstituted DPP derivative was also prepared. The last point of this thesis was the study of the incorporation of formyl functional groups into the skeleton of key N,N'-ethyladamantyl DPP derivative.
Nature-inspired macro cyclic systems for bioorganic applications
Prekopová, Terézia ; Cigánek, Martin (referee) ; Krajčovič, Jozef (advisor)
The bachelor thesis deals with nature-inspired macrocyclic compounds and their possible use in organic bioelectronics. The theoretical part of this bachelor thesis introduces semiconductor materials in organic bioelectronics and provides a general overview of selected classes of macrocyclic compounds currently occurring. It includes their history, properties, reactivity and use in various industries. An important point of this part are cyclodextrins, which are characterized by their high biocompatibility and affinity for a wide range of guests depending on the structure of the cyclodextrin. They are capable of molecular recognition to form inclusion complexes with guest particles. The work also deals with chemical modifications of cyclodextrins in order to improve selected physicochemical properties and practical applications of cyclodextrins. The experimental part consists of the synthesis, purification and characterization of key macrocyclic -cyclodextrin derivatives selectively modified at position 6 of one glucopyranose unit for the synthesis and study of advanced supramolecular structures for potential applications in organic bioelectronics.
New derivatives of diketopyrrolo[2,3-f]indole (DPIs) for organic electronics
Šípek, Jiří ; Richtár, Jan (referee) ; Cigánek, Martin (advisor)
This bachelor's thesis deals with semiconducting materials based on diketopyrroloindoles, their preparation and possible applications. In the theoretical part of the thesis, a current overview of the issues of organic electronics and photonics is presented, and technologies using the potential of organic molecules to behave as semiconductors capable of transmitting electrical energy are presented. A brief history highlights important milestones for organic conductive molecules and polymers, including important categories of high performance organic pigments and dyes such as diketopyrroloindoles (DPI). In other parts of the work, the synthetic approaches known so far in the preparation of DPI themselves are summarized, with a focus on their thiophene analogues and related derivatives. In the experimental part, the preparation of the basic molecule of the DPI skeleton is described. Finally, three derivatives differing in the character of the aliphatic side chain from a series of branched, linear and bulky substituents prepared by means of N,N'alkylation reactions are presented.

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